Non-state actors include environmental non-governmental organizations (NGOs), research NGOs and industry NGOs. Each NGO has its own constituency and represents specific interests. These non-state actors influence the negotiating process in many ways. In general, non-state actors do not serve the interests of any individual country. NGOs thus raise public awareness on the issue and link it with the daily priorities of people. They help to re-define the problem for the public, and they raise the transparency of the policymaking processes. They try to ensure the accountability of the negotiating processes and the effectiveness of the outputs. However, some industry NGOs may actually wish no outputs.

The key family of climate NGOs is the Climate Action Network (CAN) which consists of around 300 members. It has five major branches: Climate Network Europe (CNE), Climate Network Africa (CNA), Climate Action Network South-East Asia (CANSEA), Climate Action Network-South Asia (CANSA) and the U.S. branch. Some of these networks are not functioning optimally. CAN aims to develop a common position for NGOs worldwide that work on climate change related issues. Major international NGOs include Greenpeace and World Wide Fund for Nature (WWF). Major Southern NGOs include the South Centre in Geneva, the Centre for Science and Environment in New Delhi, and the Center for the Sustainable Development of the Americas.

At least one NGO provides detailed neutral reports of the daily negotiation process (see the Earth Negotiations Bulletin (ENB) of the International Institute for Sustainable Development). Other environmental NGOs provide critical perspectives and analysis of the issues being covered in the negotiations (see the newsletter ECO). Yet other NGOs provide regional perspectives (see Hotspot by CNE; CLIME ASIA by CANSA, IMPACT by CNA). Many environmental NGOs write scientific and position papers to influence the negotiations. They form coalitions to support the negotiations and they make common presentations of their positions. They conduct evaluations of national implementations and monitor the work of governments. Finally, some international experts from research NGOs also help the delegations of the small island States to actually formulate and negotiate national negotiating positions. In addition it is useful to know that the United Nations Non-Governmental Liaison Service produces the Environment and Development File in which it sums up key issues in different negotiations. It also covers the climate change negotiations for other negotiating groups.

However, all NGOs do not have the same opinion. There is a conflict between the Northern and the Southern NGOs on the definition of the issues. "While the former argue the need for curbs to be placed on economic growth, the latter argue that the worst problems are created by industry and over-consumption in the North and by inequalities in the global economic system" (McCormick 1999: 60). There is a difference of opinion between those NGOs who would like to close the loopholes and those who would like to be innovative in the process of identifying solutions to keep countries on board.

There are also many epistemic or scientific groupings. The international epistemic community consists of the scientists associated with the Intergovernmental Panel on Climate Change. In addition researchers from various institutions world-wide are active in the negotiation process. From the South these include those from the Bangladesh Centre for Advanced Studies, the Tata Energy Research Institute in New Delhi, the Southern Centre for Energy and Environment in Harare, the ENDA Tiers-Monde in Senegal, etc. Sometimes it is difficult to differentiate between a scientific group and an environmental group. From the North, these include the Foundation for International Environmental Law and Development, the International Institute for Sustainable Development, the World Resources Institute, the Institute for Environmental Studies Amsterdam and the Stockholm Environment Institute.

Then there are industry NGOs. These include green industry NGOs like the World Business Council for Sustainable Development (with its many branches), the Business Council for a Sustainable Energy Future, the Insurance Industry Initiative for the Environment and the Pew Center on Global Climate Change (with members like United Technologies, Intel, AEP, DuPont, British Petroleum, Shell, Toyota, Boeing, ABB, Lockheed Martin, Enron and Edison International). There are also other industry NGOs who favour waiting for complete scientific evidence before far-reaching action is taken. These include the Global Climate Coalition, the Coalition for Vehicle Choice (and its Global Climate Information project) and the Climate Council. There are also middle-of-the-road NGOs like the International Climate Change Partnership, the International Chamber of Commerce and the European Roundtable of Industrialists (Kolk 1998).

Finally, there are observers from banks, other UN organizations like UNDP, UNEP and the International Organization for Standardisation (ISO) and there are national and international journalists who organize a series of press conferences. The number of participants is increasing. Ten thousand people attended COP-3 and the same number is expected at COP-6.